Life cycle of local Java objects created during a method call

Question

In a method call, if I create an object during that call. When are those objects garbage collected?

Are they placed on the heap and then garbage collected along w

Answer 1

This is not so easy - in the very end every object is created in some method.

The VM / compiler needs to make escape path analysis to detect if a reference of this object in some way can escape - imagine calling newObject.toString(). You and me know (hope) that this will do no harm and the object is still not referenced, as it will not link itself to a global variable. But the VM dows not.

While a modern VM will do such analysis and treat real short lived objects special in garbage collection, from a "high level" point of view they are just objects. Everything else is sophisticated low level optimization.

And anyway, as duffymo says - when exactly this objects are freed is uncertain.